[quote=@Rtron]
[@Ploxerdon]

He's literally throwing away his chance at the Grail. He could have commanded Roland to obey his commands. Thus he would have saved himself a lot of trouble.

And he has one left regardless. One option just leaves him with a servant.
[/quote]

I recall somebody in the series trying that, it doesn't work.
And he doesn't have one left regardless if he plays it smart.